An analysis of РВВ clinical features showed that their total duration was 4.1 ± 0.3 weeks. In children with RB, the duration of exacerbations did not differ significantly and was 3.8 ± 0.4 weeks. In patients with CB, the annual number of bronchitis and the total duration of cough were two times higher than in patients with RB. Bacteriological analysis showed that Streptococcus pneumonia was the most frequent causative agent of the disease in children with PBB and RB. In children with exacerbation of CB, Haemophilus influenzae was more commonly identified. At the same time, such a representative of the normal bronchial microbiome as Aerococcus viridans, was identified in 81.0 % of PBB patients, in 33.3 % of RB patients, and in 8.7 % of CB patients
